Sorry I must be confused, (happens easily) I though Marq was the dog that had bitten other dogs, and had some reactivity issues.
But really IME it can take months or longer for dogs to get along, and it can be very stressful. If I have a foster that the others don't like, or vice versa, I don't force them to be together. In a month or two you may not get them together, you could make it worse. First you have to make sure that you are in control of the situation, at no time should any dog feel threatened to the point of showing teeth. You should keep them separated except when you are actively working with the dogs. You need to work both dogs within their comfort zone. If both dogs are dog reactive that means one human per dog. You will need LOTS of desensitization. You may not notice any improvement in that short a period of time, but who ever gets the dog will appreciate the work you do.
It's alright. With 8 dogs, and the names sounding relatively alike(Misha, Marq) I understand!
I understand it will be a long and slow process. But I would like to attempt to work it out. Not only for the foster, in hopes of resolving his issue with Marq, but for Marq so he does not have to live part of his days in a crate(he's not used to it). I certainly understand it might never happen, but I also know dogs can overcome aggression and reactivity issues if given a chance and worked with in a safe, controlled environment.
The dogs are ALWAYS separated. When Spook is loose, Marq is in my room with me or locked in the crate. When Marq is loose, Spook is either in my sister's room with her, or locked in a crate. When they are switched during the day, my mom has my brother help by holding one dog a far distance from the other and releasing one dog from the crate and puts the other back into the crate. If we want to let one loose, we are in communication with each other telling each other if we are going to - not allowing for mistakes or confusion on who's turn it is to be out or in the crate or locked in the rooms.
Marq is not one bit reactive towards spook. However, no matter there WILL be one person per dog. My sister with Spook, I with Marq. Or, if she proves to not be able to read and handle Spook as well(because I am the more knowledgeable and experienced one when it comes to behavior for I have read more and researched longer), I will take spook and she will take Marq.
Not only will we be working him through this little reactivity issue(though the rescue is not at all concerned with the fact that he doesn't get along with an intact dog), we will also be working more on sit, down, stay, come and loose leash walking. He knows sit, but I would like to get a rock solid sit no matter the distractions. He listens to his name and come, but again... just want to proof the behavior. Other than that, he truly is just a wonderful dog.
I understand a bit about the process of desensitization. I understand it must be taken extremely slowly. I plan to reward for good behavior, and will increase the criteria(closeness to Marq) over a very long and extended time period. I will not try to treat his aggression with aggression, but rather read his signals clearly and diffuse any kind of barking, lunging or snapping before it happens. (We've already begun to learn his signals. He at first usually sniffs, stares and stands still, and then reacts.) Right now we've only been continually getting Spook used to Marq through use of the crate. When at first the sight of Marq would get him going, now Spook can usually be alright with Marq in sight. What we'd like to do is to get them out of crates, both on leash and on opposite sides of the room relaxing and not paying attention to each other. I will work in proofing Marq's down, and I hope to be able to place Marq in a supervised down(one handler per dog) and slowly work Spook into coming closer and closer to Marq without reacting. I don't honestly believe this will be a huge problem, until Spook sniffs Marq. The sniffing seems to be teh source of the problem and hte start of all the reactivity issues.
